Bituminous flame resistant compositions and articles coated therewith



' sesses a number of drawbacks.

Patented June 1, 1948 I UNITED STATES cases i i m.

PATENT OFFICE nrrmumous FLAME ansrs'ran'r comrosmons AND narrows con-ran'rnnanwrrn John w. Olson, 11mm on Hudson, is. r., and

Charles W. Beohle, Sycamore, Iil.,

assignora to Anaconda Wire and Cable Company, a corporation of DelawareNo Drawing. Application mm 15, 1941',

a Serial No. 415,145

a 11 Claims.

.This invention relates to flame-resistant compositions, and iscbncemedparticularly with the provision of a new synthetic organic fiameresistant composition having-flame-resistant properties more uniformthan and superior to the corresponding properties of heretofore known.orsanic flame-resistant materials. The invention further contemplatesarticles of manufacture comprising a base structure having thereon acoating of the new flame-resistant composition.

Organic flame-resistant materials have lon been used to reduce theinfiammability of articles composed either wholly or in part ofcombustible organic substances. For example, electric wires insulatedwith rubber and surrounded by an organic fibrous jacket impregnated withalphaltic moisture-proofing compounds have been coated withflame-resistant compositions to lessen the infiammability oi theinsulation and completion of the distillation of fatty materials, suchas tallow. It is pitchy in character, usually black in color, and rathersticky even at ordinary temperatures, although its softening point isusually quite high. Upon heating to a temperature sumciently above itssoftening point, it becomes fluid, and in this condition it may beapplied in the form of a relatively thin coating to i wire, roofingsheets, and other articles.

Stearin pitch as a flame-resistant material for '2 use on wires, roofingmaterials, and the like pos- In the first place, its flame-resistantproperties are extremely variable, depending upon the particular typeand grade of material from which it is produced, and further dependingupon the manner in which it is produced. At one extreme, some commercialstearin pitches are quite readily inflammable and are thereforevalueless where flame-resistance is a desired quality. As the otherextreme, some commercial stearin pitches possess very goodflame-resistant characteristics. Other grades of stearin pitch fallbetween these extreme in their flame-resistant properties. It istherefore difficult consistently to procure stearin pitch of uniformlygood flame-resistance. In, the second place, stearin pitch forflame-resistant uses is a relatively expensive commodity, and its priceis .subject to considerable fluctuation fromtime to time. In the thirdplace, the natural stickiness tiv of stearin pitch renders itunsatisfactory as a finishing coat on articles, such as wire or sheetroofing, which are coiled, rolled or stacked for 7 shipping. Althoughgenerally such articles are best made flame-resistant by applying thestearin l0 pitch as the final coating, this is not usually practicablebecause when the wire or roofing is coiled or rolled the stearin pitchcauses the adjacent 3! turns or layers to stick together.

The present invention provides a new and imlii iiproved flame-resistantcomposition which can be Zimanufactured from readily available materialsat a cost considerably less than the average price 5 of stearin pitch;which can be manufactured with :l-uniformly high flame-resistantproperties; which 9'. may be made much less sticky than stearin pitch;

and which with these advantages can be made even more flame-resistantthan the best grades of stearin pitch heretofore available.

The new flame-resistant composition of the present invention is of suchcharacter that it may be applied to the surface of an article and formsthereon a hard permanent coating. It is stable at temperatures incidentto its normal use, but is. characterized by pulling and coking with theformation of an intumesced, difiicultly combustible cokymass whenexposed to flame. The composition comprises bitumen which imparts to thecomposition the property of forming a coky mass upon burning, to whichbitumen has been added a substance selected from the group consisting ofsulphated and phosphated derivatives of a substance of the groupconsisting of higher fatty acids, higher fatty acid esters, and higherfatty acid alcohols, the sulphated or phos-' 40 phated derivative beingcharacterized by pulling and becoming highly intumescent when exposed tofiame. Compounds containing sulphated or phosphated petroleum sludgederivatives as substances characterized by pulling and becoming highlyintumescent when exposed to flame are described and claimed' in ourcopending application Serial No. 415,144, filed October 15, 1941.

Bitumen is not highly flame-resistant and is incapable of impartingflame-resistance to ato ticles to which it is applied. This probably isdue to the fact that when bitumen is ignited on the surface of aninflammable article, any coky masses that may be formed are in suchclose contact with the inflammable article itself that combustionproceeds quite readily. However,

' phosphated derivatives of fatty acids, fatty acid particular of closecontact with readily ble material which would enable it to burnrelatively easily, and at the same time the intumesced coky mass servestoinsulate underlying inflammable material from the flame. Bitumens, andparticularly asphaltic bitumens of at least moderately high softeningpoints (upwardsof 175 F.) are especially satisfactory vehicles for thecomposition.

Especially satisfactory vehicles for the new flame-resistantcompositions are composed of a bitumen of relatively high softeningpoint in admixture with an oily tempering agent. The

oily tempering agent may be virtually any vegetable, animal or fish oil,or fatty acid derived therefrom. Drying oils are highly satisfactory foruse as the oily tempering agent but semi-' drying or non-drying oilshave been used with success. Such oils in admixture with the bitumen,while lowering the softening point of the mixture, increase itsweather-resisting properties and make it rather rubbery in quality, thus1 reducing its tendency to become brittle when cold; or fluid orsemi-fluid when warmed to.a moderately high temperature substantiallybelow its softening point. Oils capable of thus modify ing theproperties of asphaltic materials and similar bitumens are well known,and it is such oils that are embraced by the term oily tempering agenThe sulphated and phosphated derivatives employed in the new compositionare those derivatives of higher fatty acids, .higher fatty acid esters,and higher fatty acid alcohols containing sulphur-oxygen orphosphorus-oxygen radicals, such as sulphate, sulph'one, and phosphateradicals, which are characterized byputting and becoming highlyintumescent when exposed to flame. These compounds by' themselves arenot especially flame-resistant, but in combination with bitumen formcompositions having excellent flame-resisting properties. A very largenumber of sulphated and phosphated derivatives of fatty acids, fattyacidesters and fatty acid alcohols possess the requisite property ofIpufiing and becoming intumescent when exposed to flame. Whether or notany particular compound possesses this property is readily ascertainedby the simple test of exposing a small sample on a spatula to a flame,and observing whether or not it puffs and becomes intumescent.

The sulphated or phosphated derivatives employed in the new, compositiongenerally are prepared by treating fatty acids, fatty acid esters,

or fatty acid alcohols with sulphuric or phosphoric acid (or equivalentsulphating or phosphating agent). The most readily available derivativesof this class are those prepared by treating fatty acid oils, especiallyanimal, fish or vegetable ofls containing fatty acid glycerides,

with concentrated sulphuric acid, or less commonly with concentratedphosphoric acid. Such treatment results in a complex reaction mixtureusually containing, among other substances, a

proportion of organic sulphates (or phosphates) lactones, varioustypesof esters, and some polymerization products. The particularcomposition' of the reaction mixture is immaterial to the 4 invention,however, for in general sulphated or esters. and-fatty acid alcohols.and ly such derivatives of fatty acid oils (especially animal, fish orvegetable oils), may be used with success in preparing the newcomposition.

The sulphated or phosphated derivatives prepared merely by treatment offatty acid oils (or other fatty acid material or' compound) are acidicin reaction. Derivatives having an a'cid reaction areundesirable formany of the uses to which the new composition is adapted, andaccordingly it is,preferred to employ neutralized sulphated orphosphated derivatives. Such neutralized derivatives generally areprepared by first washing with an aqueous salt solution (e. 3., so-

dium chloride or sodium sulphate solution) the reaction productresulting from treatmmtof the oil or other substance with sulphuric orphosphoric acid, and then treating the washed reaction product withv analkaline agent, such as sodium or ammonium hydroxide, in suflicient Iamount to render the product substantially neutral.

The sulphated and phosphated derivatives which have been neutralizedwith the common neutralizing agents such as sodium hydroxide or ammoniumhydroxide are water-soluble. This property renders the materialunsuitable for uses involving exposure to moisture, as, for example,

exposure to the weather. It is therefore preferred to employwater-insoluble neutralized sulphated or phosphated derivatives of thecharacter referred to above. Such derivatives may be preparedby-treating the sulphated product,

- after neutralization with sodium hydroxide or other neutralizing agentyielding a water-soluble product. with a salt of a metal capable offorming an insoluble derivative.-- Calcium salts. copper salts, aluminumsalts, barium salts, and lead" salts are representative of the metalsalts capable of forming water-insoluable sulphated or phos- Suchinsoluble derivatives phated derivatives. also may be prepared byneutralizing the acidtreated fatty acid oil or other fatty acidmaterial, after washing, with the hydroxide of a metal capable ofprecipitating a substantially waterinsoluble derivative. Forexample,calcium hydroxide may be so employed.

Although it is possible to employ with success the sulphated orphosphated derivatives of fatty acids, fatty acid esters, and fattyacidalcohols generally, it is preferred to employ sulphated or phosphatedderivatives, and particularly sulphated derivatives, of fatty acid oils.By the term "fatty acid oils" we mean those oils, either natural orsynthetic, composed largely of free fatty acids or fatty acid alcoholsor esters (such as fatty acid glycerides), and especially we meannatural animal, fish or vegetable oils rich in such a fatty acidconstituents. Derivatives prepared from fatty. acid oils, especially thesulphated derivatives, are preferred because they are readily available,comparatively inexpensive, and in general yield compositions accordingto the invention which have exceptionally highflameresistant properties.

The sulphated-or phosphated product should be resistant to thermaldecomposition at the temperatures to whichit must be heated in preparingthe composition and applying it to articles. For this purpose thesulphated or phosphated product ordinarily should be'resistant tothermal decomposition at elevated temperatures up to at least 300 F.sulphated and phosphated derivaim m tives of fatty acids, fatty acidesters, and" fatty to a temperature at which it becomes fluid, and

the phosphated or sulphated derivative may then be added and the mixturestirred to produce the composition. The. bituminous composition soproduced may be used directly to ccat articles, or it may be cut backwith a suitable solvent or treated to produce an emulsion in any of theways known in the art to produce thin liquid bituminous coatingcompounds.

- .The sulphated or phosphated derivative may dissolve in the bitumen,or it may be finely dispersed therein, and in either'case an effectiveflame-resistant composition is produced. Generally, however, thesulphated and phosphated derivatives of fatty acids, fatty acid esters,and fatty acid alcohols are soluble in and otherwise thoroughlycompatible with the bitumen.

Ordinarily the sulphated-or phosphated compound should' be used in anamount equal to about 1% to by weight of the composition, althoughlarger amounts up to about 20% may in some cases prove desirable.. g

If desired, various'modifying agents may be added to the composition tosecure particular properties. For example, various oils, asphaltites andmineral fillers may be added to the compositions. These are modifyingagents well-known for imparting special properties to bitumens.

The new composition may be employed in the manufacture of articles whichit is desired to provide with a flame-resistant coating. The article ofmanufacture comprises abase structure having thereon a coating of theherein-described flame-resistant composition. A particularly usefularticle comprises an insulated wire comprising a metallic conductor,insulating material applied to the conductor, and on said insulatingmaterial a coating of the flame-resistant comhicle and a sulphatedproduct of petroleum hydrocar-bons is described in detail below. It isunderstood, however, that the specific composition described below isnot considered to limit the scope of the invention.

Inasmuch as the new composition is intended primarily for use as aflame-resistant coating on articles such as insulated wiresand rooflngelements, a bitumen having a softening point upwards of 175 F. should beemployed. (The softening points referred to herein are determined by theA. S. T. .M. standardized ring and ball method.) For most practicalpurposes a bitumen having a softening point from 210 F. to 250 F.

' is especially satisfactory. Bitumens of such relabitumens catch fireless readily than the softer bitumens of lower softening points. Abitumen more suitable for use in making up thenew flame resistantcomposition than a bitumen which ignites readily.

Asphalts are particularly suitable bitumens for use in preparing the newcomposition. Any available asphalt may be employed, including naturalasphalts, steam reduced asphalts', blown asphalts, and asphaltic residua(flux oils) of petroleum distillation. Especially satisfactory resultshave been obtained using an air blown flux oil having a softening pointfrom 225 F.,to 240 F. in preparing a flame-resistant composition forcoating insulated wires.

Satisfactory flame-resistant compositions may .be prepared byincorporating the sulphated or phosphated derivative of a fatty acid, afatty acid ester, or a fatty acid alcohol in the bituminous substance,without any modifying agents being added. In many instances, however, itis desirable to employ other substances in the composition to modify itsphysical properties and to enhance its flame-resistance. Oily temperingagents which increase the weather-resistant qualities of the compositionand make it less.

likely to crack in 'cold weather or. to flow or run in hot weather areespecially desirable. These oily tempering agents are desirable for thefurther reason that they can be made to increase the difllculty withwhich the bituminous base is set aflre, and hence to enhance theflame-resistance of the finished composition.- Vegetable, animal, andfish oils are well known to be excellent fluxes for asphalts and toincrease their weather-resistant properties, and such materialsconstitute the class of oily tempering agents advantageously employed inthe composition.

The oily tempering agent may be drying, semidrying, or non-drying. Amongthe I oily tempering agents which have been used with success may bementioned fish oils, such as menhaden oil, pilchard oil, sardine oil,and herring oil; flsh oil fatty acids; animal oils and fats, such aswhale oil and beef tallow; and vegetable oils, such as soy bean oil,linseed oil, cotton-seed oil, tung oil,

agent is added in suitable amount to the asphalt and other bitumenpreferably while .the latter is heated to a fluid condition. In generalabout 70% to of the asphalt is employed in admixasphalt with air at asufliciently high temperature and for a suflicient period of timetoincrease the softening point to a satisfactorily high value, say from210 F. to 250 F. Such blowing treatment .may becarried outin -con-'ventional asphalt blowing equipment and in the manner usually employedfor preparing blown asphalts. The temperature of the mixture during theblowing advantageously is about 450 F. to 600 F. It may in some cases benecessary to increase the temperature of the mixture while the blowingproceeds and as the softening point of the mixture increases. Forexample, blowing may be begun at about 450 F. and the temperature of themixture may be increased,

as blowing proceeds to an ultimate value of which catches'flre only withsca e dimculty is.

The oily tempering temperatures.

about 600 F. In general, the softening point of the asphalt-oil mixtureshould'be above 175 positions suitable for coating wires, roofingelements and the like.

The blown mixture of asphalt or other bitumen and oil or other oilytempering agent is easier to handle in commercial operations than theasphalt alone, is more rubbery than the asphalt alone, and is lesslikely to crack in cold weather and less likely to run or flow at highoutdoor In addition it is less likely to bleed through paints appliedover it on a wire or on a roofing element. It is, moreover, morediillcult to ignitethan the asphalt alone and so is a better base forthe flame-resistant composition.

' a high temperature to an ultimate softening point of 300 F. or over.Blowing to-such a high softening point is extremely hazardous, and thefying agents may be mixed with the bituminous base.

The composition is completed by incorporating the sulphated orphosphated derivative of a fatty acid, a fatty acid ester, or a fattyacid alcohol in the bituminous base. Any such sulphated derivative maybe employed in preparing the composition, .but in general it ispreferred to employ a sulphated or phosphated derivative taining veryhigh proportions of saturated constituents. Castor oil is composedlargely of the giyceride of ricinoleic acid, an unsaturated com-'-pound, and is well adapted for the preparation of sulphated orphosphated derivatives for use in the new composition. Since sulphatedcastor oil is extensively manufactured. it is a readily availablematerial for use in preparing the new composition and has ben found tobe highly eifective.

sulphated castor oil and other sulphated and phosphated derivativesresulting directly from treatment of the oil or other fatty acidsubstance with sulphuric or phosphoric acid are acidic. The presence ofacid constituents in compositions for coating such articles as wire androofing elements is generally undesirable, and accordingly it ispreferred to employ a neutralized sulphated or phosphated derivative inmaking up the flame-resistant composition. Neutrallzed sulphated castoroil is prepared by first washing the castor oil-sulphuric acid reactionmixture with a solution of sodium chloride or sodium sulphate to removeexcess acid, and then treating with an alkaline agent, such as sodium orammonium hydroxide. Neutralized products of other sulphated orphosphated derivatives may be prepared similarly.

Neutralized sulphated castor oil prepared in the manner just described(using sodiumor ammonium hydroxide) is water-soluble. The same is truein general of other sulphated or phosphated derivatives neutralized withan alkali of a fatty acid oil, especially a natural animal,

vegetable or fish oil. ,Such oils are composed largely. of various fattyacid glycerides.

The sulphated product may be prepared by treating the' oil (or otherfatty acid, fatty acid ester, or fatty acid alcohol) with concentratedsulphuric or phosphoric acid. The resulting sulphated product generallyis a complex mixture of a number of substances, usually including aproportion of organic sulphates, lactones, esters, and polymerizationproducts. Sulphated derivatives of castor oil are highly satisfactory,and since they are manufactured in large quantities to produceTurkey-red oil for the textile industry, they are readily available.Sulphated acid compounds are also effective. For example, sulphated orphosphated derivatives of olive oil, soy bean oil, rape oil, cottonseedoil, peanut oil, coconut oil, palm oil, palm kernel oil, beef tallow,menhaden oil, pilchard oil, oleic acid (red oil); etc., may be employedin place of the sulphated or phosphated derivative of castor oil.

Some oils from among those mentioned above containa higher percentage ofunsaturated compounds than others, and such oils are betteradapted tothe production of effective sulphatedor' phosphated products than arethe oils con- 'or phosphated derivatives of other oils or fatty metal orammonia caustic; Water-soluble compounds generally are undesirable foruse in the new flame-resistant composition, because many of the articlescoated with the composition must be exposed to the weather.water-soluble constituents in a composition so exposed will eventuallybe washed away. Moreover, water-soluble sulphated or phosphatedderivatives of the character employed are in many instances capable offunctioning as soaps, and are likely to cause the asphalt or otherbituminous constituent of the composition to emulsify and wash away.Consequently. it is preferred to employ water-insoluble employe" oipitate the corresponding waterinsoluble sulphated or phosphatedproduct. In

preparing the water-insoluble product in this manner, it is'preferableto employ a soluble salt of the chosen metal, as, for example, calciumchloride or copper sulphate. It is desirable also to add the metal saltprecipitant to the soluble neutralized sulphated or phosphated productwhile the latter is at an elevated temperature, preferably approachingits boiling point, as in this manner the precipitate develops in a formwhich is fairly easily separated from the residual liquor.

Water-insoluble neutralized sulphated or phosphated derivatives also maybe prepared by treating the sulphated or phosphated product, afterwashing'to remove excess acid but before neutralizing directly with thehydroxide of the metal selectedto form the insoluble material. Forexluminum, lead, barium, etc, may be,

lii o ibi ample. the washed acidic sulphated or phosphatedwater-insoluble sulphated or phosphated prod uct eminently suitable foruse in the new composition.

The particular metal compound chosen to produce the insolubleneutralized sulphated or phosphated product is not critical. Calciumsalts (or calcium hydroxide, depending upon the manner of forming theinsoluble compound) are inexpensive. and the calcium-precipitatedproduct is highly effective. In some cases it may be desirable to employa compound of some other metal so as to impart particular properties tothe insoluble product. The copper-precipitated product, for example, istoxic to fungus growths, and compositions prepared from such productsare therefore especially suitable for use where resistance tcdeterioration from fungus growth is important.

The sulphated or phosphated product, preferably neutralized andwater-insoluble, is readily incorporated in the bituminous base of thecomposition while the latter is. heated to a fluid condition- Thesulphated or phosphated derivative may beadded to the fluid bitumen, andthe mix ture may be stirred or otherwise agitated to effect thoroughadmixture of. the two components. Sulphated and phosphated derivativesof the character herein-described generally are soluble in andcompatible with bituminous vehicles, so that no particular difflculty isexperienced in mixing the two together. An amount of the sulphated orphosphated product from 1% to by weight of the composition is generallyeifective for producing a highly flame-resistant composition.- A smallamount within this range is effective if the bituminous base itselfpossesses moderate flame-resistance, whereas a relatively large amountwithin the stated range is desirable if the base itself is fairlyreadily ignited. For most purposes, using an asphalt-oil base blown to asoftening point of 210 F. to 250 F., about 3% to 5% by weight of thesulphated product results in a composition having excellentflameresistance. r

The new composition may be applied to articles in much the same mannerin which stearln pitch has heretofore'been applied. For example, thecomposition may be applied to an insulated wire by drawing the wirethrough a molten bath of residual liquor. The precipitate thus obtainedwas incorporated by stirring into the air-blown asphalt-fish 011 basewhile the latter was heated to a fluid condition.

7 About 5% of the insoluble neutralized sulphated product by weight ofthe composition, was employed. The resulting composition was applied toan insulated wire having an insulation of rubber surrounded by anasphaltimpregnated'cotton braid by drawing the wire through a moltenmassof the composition, and thence through a wiping die to removeexcess, composition. Upon cooling the wire. the coating was found to becontinuous, adhering, and considerably less tacky'or sticky than asimilarly applied coating of stearln pitch. The wire was subjected tothe standard underwriters flame test and passed readily. A wire coatedin a a having a ball and ring softening point of about 80 F. was heatedto a fluid condition and mixed with coconut oil in the proportions ofabout 90% asphaltic residuum and about 10% by weight of the oil. Theresulting mixture was blown with air until its softening point wasincreased to about 225 F. to 240 F. A water-insoluble neutralized'sulphated derivative of castor oil was prepared by treating commercialTurkey red oil at a temperature approaching its boiling point withcopper sulphate, and separating the resulting precipitate from theresidual liquor. The precipitate thus obtained was incorporated in theblown asphaltic base while the latter was heated to a fluid temperature,in the proportions of about 5% by weight of the insoluble sulphatedproduct. to 95% of the bituminous base. The composition thus preparedwas applied to a wire having a rubber insulation surrounded by anasphalt-impregnated cotton braid by drawing the wire through a moltenmass of the composition and thence through a wiping die. The thusthecomposition, and thence through a wiping die to remove excess.composition. It may be applied to roofing sheets or other roofingelements by brushing the molten composition on to the surfaceofthesheet, or by othermethods commonly employed for coating roofingelements with bituminous materials or with stearln pitch. The followingspecific examples illustrate the preparation of a flame-resistantcomposition in accordance with the invention:

Example A.An air-blown asphalt having a softening point of about 140 F.was heated to a fluid condition and mixed with menhaden oil in theproportions of about 90% asphaltand 10% oil. The resulting mixture wasblown with air at a temperature 'of about 500 F. until its softeningpoint had been raised to between 225 F. and

proaching its boiling point, with calcium chloride,-

and separating the resulting precipitate from the coated wire, uponcooling, was found to have a smooth, non-tacky and non-sticky surfaceresembling patent leather in appearance and feel. The wire was subjectedto the underwriters flame test and passed easily. A wire coated with theblown asphaltic-residuum-coconut-oil base to which no sulphated orphosphated derivative has been added'failed to pass the underwritersflame test, although the asphalt alone burned with some coke formation.

It is evident. from the foregoing examples that the new composition mayreadily be made sufllciently flame-resistant so that a rubber-insulated,fabric-covered wire coated therewith easily passes the rigidunderwriters flame test. In this connection it may be noted that neitherthe vehicle of the'new composition nor the sulphated or phosphatedderivative are by themselves particularly flame-resistant, and neither,when coated on a rubber-insulated wire, will by itself enable the wireto pass the flame test. The sulphated or phosphated derivative, however,puffs and becomes highly intumescent in the flame, and in consequence ofthis property the vehicle in which it is incorporated is caused to puffand form an intumescent, diiflcultly combustible coky mass which isspaced from underlying inflammable material and so protects itfromignition by a flame.

The new flame-resistant composition can be made so as to be much lesssticky than stearln pitch by employing a non-sticky bituminous (or Y s.I

" 11 other) vehicle. A bituminous vehicle or base prepared from asphaltand an animal, fish or vegetable oil is, generally speaking, much lesssticky than stearin pitch, and the composition prepared from such a baseis correspondingly The new composition can be made considerably moreflame-resistant than even the best grades of stearin pitch andsuccessive batches of the new composition can be prepared with uniformlyhigh flame-resistant properties. Because of the excellentflame-resistant qualities of compositions prepared according to theinvention, it is possible to apply such compositions to-insulated wirebeneath relatively inflammable coatings of asphalt or wax withoutdestroying the flameresistance imparted to the wire by the newcomposition. For example, stearin pitch has heretofore been applied towires to render themfiameresistant by first saturating the fibrousjacket on the wire with an asphaltic compound, and apply-v ing thestearin pitch over the asphalt impregnated jacket. Frequently a thin waxcoating is applied over the stearin pitch, but where flameresistance isdesired the asphaltic constituents are always applied under the stearinpitch. The new composition may be employed to saturate the fibrousjacket, and asphaltic or wax (or both) finishing coats may be appliedthereov'er;

The new composition is substantially as moisture-resistant as thestraight bituminous vehicle. Hence such compositions may be employed toreplace the asphaltic moisture-resistant saturants commonly applied towires and roofing com-- pounds, without thereby sacrificing protectionof the wire or roofing from moisture penetration. but with theattainment of a considerable increase in. protection against firehazard.

The new composition is prepared from relatively inexpensive materials,and in its preferred form may be made more inexpensively than it ispossible to procure stearin pitch.

We claim: I v

1. A bituminous flame-resistant composition capable of being applied tothe surface of an articleand of forming thereon a hard permanent coatingwhich is stable at temperatures incident to its normal use and isfurther characterized by pufiing and coking with the formation ofintumesced difiicultly combustible coky mass when exexposed to flame,said composition being in the form of an intimate mixture consistingessentially of a bitumen having a softening point upwards of 175 F., towhich has been added a substantially neutral, water-insoluble sulphatedfatty acid oil derivative characterized by puffing and becoming highlyintumescent when exposed to flame. a

3. A bituminous flame-resistant composition capable of being applied tothe surface of an article and of forming thereon a hard permanentcoating which is stable at temperatures incident to its normal use andis further characterized by pufilng and coking with the formation of anintumesced diflicultly combustible coky mass when exposed to flame, saidcomposition being in the form of an intimate mixture consistingessentially of a bitumen having a softening point upwards of175 R, anoily tempering agent of the group consisting of animal and vegetableoils, and a substantially neutral, water-insoluble sulphated fatty acidoil derivative characterized by puiiing and becoming highly intumescentwhen exposed to flame, said composition having a softening point upwardsof 175 F.

4. A bituminous flame-resistant composition capable of being applied tothe surface of an article and of forming thereon a hard permanentcoating which is stable at temperatures incident to its normal use andis further characterized by pulling and coking with the formation of anin- A, tumesced difiicultly combustible coky mass when posed to flame,said composition being in the form of an intimate mixtureconsisting'essentially of a bitumen having a softening point-upwards of175 It, to which has. been added a water-insoluble substance selectedfrom the group consisting of sulphated and phosphated derivatives of asubstance of the group consisting of i higher fatty acids, higher fattyacid esters, and 1 higher fatty acid alcohols, the sulphated orphosphated derivative being characterized by puiiingvand becoming highlyintumescent when exposed to flame. 1

2. A bituminous flame-resistant composition capable of being applied tothe surface of an article and of forming thereon a hard permanentcoating which is stable at temperatures incident to its .normal use andis further characterized.

by pufiing and coking with the formation of an intumesced diiiicultlycombustible coky mass when 6. A bituminous flame-resistant compositioncapable of being applied to the surface of an ar-' by pufling andbecoming highly intumescent when exposed to flame.

7. A flame-resistant insulated wire comprising a metallic conductor,insulating material applied to said conductor, and on said insulatingmaterial a coating or a bituminous flame-resistant composition which isstable at temperatures to which the wire is normally subjected and whichis characterized by pumng and coking with the formation of an intumesceddiilicultly combustible coky mass when exposed to flame. saidcomposition being in the form of an intimate mixture consistingessentially of a bitumen having a softening point upwards of 175 F.. anda substance of the group consistingof sulphated and phosphatedderivatives of a substance of the group consisting of higher fattyacids, higher fatty acid ataxi esters, and higher fatty acid alcohols,the sul- 'a metallic conductor, insulating material applied to saidconductor, and on said insulating material a coating of a'bituminousflame-resistant composition which'is stable at temperatures to which thewire is normally subjected and which is characterized by pufling andcoking with the formation of an intumesced dimcultly combustible cokymass when exposed to flame, said composition being in the form of anintimate mixture consisting essentially of a bitumen having a softeningpoint upwards of 175 F. and a substantially neutral, water-insolublesubstance of the group consisting of sulphated and phosphatedderivatives of a substance of the group consisting of higher fattyacids, higher fatty acid esters, and higher fatty acid alcohols, thesulphated or phosphated derivative being characterized by putting andbecoming highly intumescent when exposed to flame.

9. A flame-resistant insulated wire comprising a metallic conductor,insulating material applied to said conductor, and on said insulatingmate-. rial a coating of a bituminous flame-resistant composition whichis stable at temperatures to which the wire normally is subjected andwhich is characterized by pulling and coking with the formation of anintumesced diflicultly combustiblecoky mass when exposed to flame, saidcomacterized by pulling and becoming highly in-- tumescent when exposedto flame.

10. A flame-resistant insulated wire comprising a metallic conductor,insulating material applied to said conductor, and n said insulatingmaterial a coating of a bituminous flame-resistant compos'ition which isstable at temperatures to which the wire normally is subi acted andwhich is-characterized by pufling and coking with the formation of anintumesced difflcultly combustible coky mass when exposed to flame, saidcomposition being in the form of an intimate mixture consistingessentially of an asphaltic bitumen having a softening point upwards of175 F.. an oily tempering agent of the group consisting of animal andvegetable oils, and a substantially neutral, water-insoluble sulphatedfatty 14 acid oil derivative characterized by pulling and Becominghighly intumescent when exposed to ame.

11. A flame-resistant roofing material comprising a backing sh'eethaving thereon a coat- -ing of a bituminous flame-resistant compositionwhich is stable at temperatures to which the roofing normally issubjected and which is characterized by pulling and coking with theformation of an intumesced dimcultly combustible coky mass when exposedto flame, said composition being in the form of an intimate mixtureconsisting essentially of a bitumen having a softening point upwards01175" F.. to which has been added a substantially neutral,water-insoluble substance of the group consisting of sulphated andphosphated derivatives of a substance of the grou consisting of higherfatty. acids, higher fatty acid esters, and higher fatty acid alcohols,the sulphated or phosphated derivative being characterized by pumng andbecoming highly intumescent when exposed to flame. JOHN W. OISON.CHARLES W. BECHLE.

REFERENCES crrnn v The following references are of record in the file ofthis patent: e

UNITED STATES PATENTS Number Name Date 2,339,853 Hemmer Jan. 25, 19442,305,325 Snyder Dec. 15, 1942 2,305,324 Snyder. Dec. 15, 1942 2,299,469DAntal Oct. 20, 1942 1,969,904 Sadtler .1 Aug. 14, 1934 1,888,295 SmithNov. 22, 1932 1,872,358 Styer Aug. 16, 1932 1,856,756 Fugiola. May 3,1932 40 1,842,857 Bolgar Jan. 26,1932 1,834,552 Sadtler et a1. Dec. 1,1931 1,720,487 Lichtenstein "July 9', 1929 1,663,577 Watson Mar. 27,1928 1,444,051 Allison Feb. 6, 1923 1,262,302 Boeck-ing .Apr. 9, 19187.195 Matter Jan. 4, 1916 713,190 Zimmer Nov. 11, 1902 FOREIGN PATENTSNumber Country Date 519,119 Great Britain Mar. 18, 1940 OTHER REFERENCESI5 J I6 Certificate of Correction Patent No.'2,442,707. t 4 June 1,1948.

- JOHN w. OLSON ET AL V I It is hereby certified that errors appear inthe printed specification of the above numbered atent requiringcorrection as follows; Column 1, line 17, for alphaltic read asp to;line 49, for- As the read At the; column 10, line 51, for has been readhad been; column 14, line 39, list of-references cited, for Fugiola readFri iola' line 42, for "chtenstein" read Lichtenstein; and'that-the saidLetters Patent s ould be read with these corrections therein that thesame may conform to the record of the case in'thePatent Ofice,

; Signed and eealed thisI7th dayof S enteniber; A.:D':1948.

moms F. MURPHY,

flammisaidmr of Patents.

